(a) Field of the Invention
The present invention relates to a separator for a fuel cell having channels for self-humidification, and, more particularly, to a separator for a fuel cell having channels for self-humidification in which a plurality of cathode intake/exhaust manifolds and anode intake/exhaust manifolds are formed such that directions of fuel flow in neighboring channels are opposite to one another and humidity is transferred from the side containing more humidity to the side containing smaller humidity through a GDL, thereby performing self-humidification without a separate humidifying apparatus.
(b) Description of the Related Art
Since transmittance of hydrogen ions is deteriorated if humidity is insufficient in a fuel cell stack, gas is supplied to the fuel cell stack in a state of being humidified. In a polymer electrolyte fuel cell, which uses a polymer electrolyte membrane, if humidity is deficient, transmittance of hydrogen is deteriorated. In addition, contact resistance between electrodes and a polymer electrolyte membrane is increased by contraction of an electrolyte membrane.
On the contrary, if there is too much humidity, a flooding phenomenon wherein moisture is condensed on the electrodes may occur, thereby preventing reaction gas from being diffused so as to deteriorate performance of a fuel cell.
In order to solve these problems, a humidifier is sometimes installed in an inlet of a fuel cell stack so as to regulate humidity at an inlet, and at the same time, there was an attempt of improving a shape of a separator so as to smoothly exhaust water generated in the stack. However, if a separate humidifier is installed, size of a fuel cell system is increased, and there may be pressure loss in the humidifier.
Accordingly, among other things, a method for humidifying a fuel cell stack without using a separate humidifier and for solving a flooding phenomenon is needed.